Pressure cooker safety device

ABSTRACT

A safety device for a steam pressure cooker has a gasket lifter mechanism for selectively lifting the sealing gasket of the pressure cooker to provide for an escape of steam prior to each opening of the cooker, and preferably also whenever the cooker lid is incorrectly positioned relative to the cooking vessel.

ilniicd Staten Patent Ulocrlimlcr 1 Web. 29, 11972 [54] PRESSURE CUOKER SAlFlE'lFY DlEVllClE References Ci Inventor! Karl-Oskar Oberlinder, Geislingen am UNITED STATES PATENTS Stage Germany 2,584,759 2/1952 Swenson ..220/55.3 X [73] Assigneez Wumembergische Memuwamniabm, 3,559,839 2/1971 Seethaler ..220/55 PC Ge'slmge" am Stage German-V FOREIGN PATENTS 01R APPLICATIONS [22] My 1,334,877 7/1963 France ..220/40 s [21] Appl. No.; 54,705

Primary ExaminerGeorge T. Hall I Attorney-Luc P. Benoit Foreign Application Priority Data July 17, I969 Germany ..P 19 36 505.0 [57] ABSTRACT A safety device for a steam pressure cooker has a gasket lifter [52] US. Cl. ..220/55.3, 220/ S, 220/55 PC mechanism for selectively lifting the sealing gasket of the pres- [51] llnt. Cl. ..A47j 27/08, Bd 45/00 sure cooker to provide for an escape of steam p r to h [58] Field OI Search ..220/55.3,55 Pc,40s Opening of the cooker, and Preferably also whenever the cooker lid is incorrectly positioned relative to the cooking vessel.

, l 25 77 79 72 is 11770 3 PATENTEn Fzsze me SHEET 1 OF 5 2s 11 19 12 16 III 70 INVENTOR KARL-OSKAR OBERLANDER ATTORNEY PATENTEDFEB 29 I972 3, 645 8 SHEET 2 [IF 5 Fig.3

PATENTEUFEBN I973 SHEET 5 OF 5 Fig. Q

PRESSURE COOKER SAFETY llllEVllCE BACKGROUND OF THE INVENTION 1. Field of the Invention The subject invention relates to cooking vessles and, more particularly, to safety devices for steam pressure cookers.

2. Description of the Prior Art There is known a pressure cooker type in which the lid and the rim of the cooking vessel are in a conventional manner provided with mutually spaced claws which in the locking position of the cooker interfit in the manner of a bayonet catch. The safety device of this known cooker has a bolt which is mounted in the lid handle for radial movement relative to the cooker lid, and which is biased by a spring in a direction toward the lid rim. In that quiescent state, a lug provided on the bolt projects through an opening in the lid rim and lifts the sealing gasket of the cooker from the sealing surface.

This known safety device is arranged at the location of a claw of the cooker lid. A plurality of claws of the cooking vessel have inclined lateral edges on which the lower part of the lug of the safety device travels during rotation of the lid in locking position. In this manner, the lug is pressed against its spring bias away from the lid rim and thus permits an engagement of the scaling gasket with die sealing surface. This process is reversed during opening of the lid, so that the lug of the safety device relifts the gasket whereby pressurized steam in the cooker which is still present at the time of opening of the cooker can escape therefrom.

These known steam pressure cookers have several disadvantages. To be sure, it is provided that the lid handle in the lid locking position shall be in registry with the vessel handle; and the lug of the safety device will in that position with certainty engage a vessel claw, thereby enabling a rise in steam pressure. However, there is no locking device which prevents the lid from being attached to the vessel in an incorrect position in which the lid and vessel claws are also able to interfit rotationally. Since a rise in steam pressure is also possible in that incorrect position, there is no guarantee of safe operation despite the provision of a dog which laterally defines a radial edge as a catch against rotation in the wrong direction.

Moreover, it is possible with this known cooker type that steam pressure can already build up when the lug of the safety device has reached the end region of an inclined claw edge while the vessel and lid claws are insufficiently interlocked. This is particularly the case when the lid is positioned on the vessel at an angular displacement of the lid handle and the vessel handle which exceeds the specified value; as well as when the lid is rotated in the wrong direction, which is possible when not all vessel claws are provided with catch edges and the lid is positioned at an excessive angular displacement.

In these cases, the rising steam pressure blasts the lid off the vessel.

The required safety against opening under pressure is even lacking when the lid has been correctly positioned and locked. To be sure, the lug of the safety device slides immediately into lifting position upon opening in the correct rotational direction, but the claws are disengaged and the lid is released during a rapid rotational movement, which is not impeded in any manner, before even a portion of the pressure differential has a chance to equalize itself.

In that case, the lid is also blasted upwardly whereby a danger of considerable injury to the operator exists. If this rapid opening is effected by lid rotation in the wrong direction, which is not inhibited in any manner, the claws are practically completely disengaged before any pressure equalization can take place, since the lug of the safety device is then only in the last moment capable of sliding into lifting position. The power with which the lid is blasted off is then even greater.

Further models of the initially mentioned type are known in which the safety device also has a pressure element which acts through an opening in the lid rim on the sealing gasket and which is slidably mounted in the lid handle and is coupled with a locking element. The safety device of these known appliances operates in such a manner that the pressure element in its rest position does not lift the gasket seal, but is moved into lifting position upon actuation of the locking element as is necessary for an opening of the lid from the locking position. In this manner, steam pressure which is still present in the cooker already becomes noticeable through escaping steam prior to the initiation of the rotary lid motion, and the largest part of the pressure is decreased by the time the lid has been rotated in the unlocked position. Accordingly, those safety devices largely avoid an opening of the cooker under pressure; but they are unable to eliminate the possibility of a lid placement in an incorrect position so that steam pressure can rise while the locking elements are insufficiently engaged resulting in a forceful blasting off of the lid either instantly or during the opening of the cooker.

SUMMARY OF THE INVENTION The subject invention avoids these disadvantages and materially improves the safety of pressure cookers, as will become apparent in the course of this disclosure.

From one aspect thereof, the subject invention provides a safety device for a steam pressure cooker, which steam pressure cooker comprises a cooking vessel, a lid connectable to and selectively removable from the cooking vessel, a sealing surface and a gasket engaging the sealing surface for releasably sealing the lid relative to the vessel.

The safety device under consideration comprises, in combination with the pressure cooker, first means operatively associated with the gasket for selectively lifting the gasket from the sealing surface to permit the escape of steam from the vessel, and second means connected between the lid and cooking vessel for locking the lid against removal from the cooking vessel within a locking range and for selectively releasing the lid for removal from the vessel.

The safety device under consideration further includes third means connected to the first and second means for actuating the first means to lift the gasket from the sealing surface prior to each release by the second means of the lid for removal from the vessel, and fourth means operatively associated with the gasket for selectively lifting the gasket from the sealing surface to permit the escape of steam from the vessel in response to displacement of the second means relative to the locking range.

It will be recognized that the safety device under consideration permits only then a sealing engagement of the gasket with its sealing surface when the lid of the cooker is correctly positioned and locked on the cooking vessel. Operation of the subject pressure cooker is thus practically free from danger and foolproof, since even a negligent operation will not lead to explosionlike removal of the cooker lid. The safety device according to the subject invention will educate even technically inexperienced housewives to correctly position the lid on the vessel, since there is only one specific lid position in which the requisite steam pressure can develop.

From another aspect thereof, the subject invention provides a safety device for a steam pressure cooker of the type mentioned above in the subject summary.

This safety device comprises, in combination with the pressure cooker, first means operatively associated with the gasket for selectively lifting the gasket from the sealing surface to permit the escape of steam from the vessel, and second means connected between the lid and cooking vessel for locking the lid against removal from the cooking vessel within a locking range and for selectively releasing the lid for removal from the vessel, as well as third means connected to the first and second means for actuating the first means to lift the gasket from the sealing surface prior to each release by the second means of the lid for removal from the vessel.

The latter safety device may advantageously be employed where considerations of economy and space are of importance. To be sure, this safety device omits the above-mentioned fourth means and their safety function. However, it still provides a considerable margin of safety relative to prior art devices, since pressurized steam is positively caused to escape from the vessel when the lid is unlocked from its correct position on the vessel.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will become more readily apparent from the following detailed description of preferred embodiments thereof, illustrated by way of example in the accompanying drawings, in which:

FIG. l is a sectional and fractional detail view of a steam pressure cooker in accordance with an embodiment of the subject invention, and along the line II in FIG. 2;

FIG. 2 is a section along the line II-II in FIG. ll;

FIG. 3 is a fractional bottom view of a lid and lid handle in the direction of the arrow III in FIG. 1;

FIG. 4 is a fractional top view of a vessel and vessel handle in the direction of the arrow IV in FIG. ll;

FIG. 5 is a section along the line VV in FIG. ll;

FIG. 6 is a sectional and fractional detail view of a modification of the steam pressure cooker of FIG. I, in accordance with a further preferred embodiment of the invention;

FIG. 7 is a sectional and fractional detail view of a steam pressure cooker in accordance with a further embodiment of the subject invention, and along the line VIIVII in FIG. 8;

FIG. 8 is a section along the line VIII-VIII in FIG. 7;

FIG. 9 is a stepped section along the line IX-IX in FIG. 7; and

FIG. 10 is a fractional top view of a vessel and vessel handle along the line X-X in FIG. 7.

DESCRIPTION OF PREFERRED EMBODIMENTS The FIGS. 1 to 5 illustrate a pressure cooker comprising a cooking vessel 1 and a lid 2. In the interest of a magnified and improved illustration, only fractions of the vessel 1 and lid 2 and of associated handle structures are shown, inasmuch as the parts which are not specifically illustrated may be of conventional design.

A stem-shaped handle 3 is attached to the vessel 1, and a stem-shaped handle 4 is attached to the lid 2. The figures under consideration show the pressure cooker in its closed condition. In this condition, the lid 2 is locked on the vessel 1 by peripherally distributed claws 6 and 7, only one pair of which is shown. The claws 6, which reach under the claws 7, are formed by inwardly bent portions of the rim 5 of the lid 2. The claws 7, on the other hand, are formed by outwardly bent portions of the vessel E. An annular gasket 8 of rubber or rubberlike material rests in the lid rim 5 to seal the vessel I and lid 2 relative to one another so as to permit a rise of pressure in the cooker.

The lid handle 4 carries a safety device which is located in a recess 9 of that handle, and which comprises a first slide 10, a second slide 11, a compression spring l2 and an actuator 37. A lug of the first slide 10 provides a first lifting element 13 which enters a corresponding opening 14 in the lid rim 5. The slide 10 further carries a bolt 16 in a stepped recess at one of its surfaces. A bore 17 is provided at a median portion of the slide 10 and the compression spring 12 is with its one end slidably inserted into that bore l7. A locking element 18 is formed by a plug projecting from the lower side of the first slide It! and beyond the lower surface of the lid handle 4. The locking element 18 is semicircularly shaped at the side thereof which faces away from the lid 2. A lug w projects from the median portion of the slide It) at a location below the springreceiving bore 117. The lug 19 substantially extends in parallel to the lifting element 13, but for a shorter distance.

The second slide 11 has in its upper region a lug which forms a second lifting element 2t that enters a corresponding opening 21 in the lid rim 5. A bore 22 for receiving the second end of the spring i2 is located in a median portion of the second slide it. A recess 23 for receiving the lug i9 is located in the second slide ll adjacent the bore 22. Two parallel slide bars 24 (see FIG. 3) project from the median portion of the slide Ill in a direction away from the second lifting element 20. A control element 25 is located below the median portion of the slide Ill and projects therefrom to below the lid handle 4. The control element 25 is semicircularly shaped at the side thereof which faces toward the lid 2.

As shown in FIG. 2, the actuator 37 has two arms 26 and 27. The arm 26 has an eye 2% by means of which the actuator 37 is pivotally mounted on the bolt 16 of the first slide It The other arm 27 is shaped in the nature of a piano key and projects laterally from the handle 4. The actuator 37 is supported relative to a wall of the handle recess 9 by means of a bearing surface 29 about which the actuator is tiltable.

The safety device under discussion may be mounted in the lid handle 4 in the following manner:

At first the actuator 37 is inserted from the side and the first slide MD from below, whereby the bolt I6 is inserted into the eye 23. The spring 12 is then inserted into the bore 17 of the first slide it). Thereafter, the second slide Ill is inserted from the end of the handle 4 adjacent the lid 2, whereby its sliding bars 24 (see FIG. 3) come to bear bilaterally at the median portion of the first slide 10. The free end of the spring 12 enters thereby the bore 22, and the lug I19 moves into the recess 23. If now the handle 4 is attached to the lie 2, then the compression spring 12 moves the first slide 10 against the end of the handle recess 9 which is remote from the lid 2. At that time the second lifting element 20 reaches through the opening 2H and presses the gasket 8 away from its sealing surface.

A first control cam 30 (see FIG. 4) at the upper side of the vessel handle 3 cooperates with the locking element 18 of the first slide M), and defines a register notch 31. A second control cam 32, which projects in a direction toward the registry notch 31, cooperates with the control element 25 of the second slide 11. A striker bar portion 33 extends between the cams 3t) and 32, as shown in FIG. 4. This striker bar portion and cams with registry notch are provided by the outline of a recess 34 in and at the upper surface of the vessel handle 3.

The safety device and the control cams under discussion cooperate as follows:

The spring 12 effects by means of the second lifting element 20 in the above-mentioned manner a lifting of the gasket 20 from its sealing surface as long as the lid 2 is removed from the vessel 1 or as long as the lid handle 4 is out of registry with the vessel handle 3. When the handles 3 and 4 move into registry during rotation of the lid 2 into the locking position, the locking element 18 slides with its rounded surface along the first control cam 30. In consequence, the first slide 10 is moved against the bias of the compression spring 12 in a direction toward the lid rim 5, and the first lifting element 13 is pressed through the opening 114 against the gasket 8. The lifting elements 13 and 20 thus lift the gasket 8 from its sealing surface. The second control cam 32 only starts to act on the control element 25 after the latter lifting operation; with such action also taking place against the bias of the compression spring 12, whereby the second slide ll is moved away from the lid rim 5 and the second lifting element 20 is withdrawn from the gasket 8. Similarly, the compression spring 12 again presses the first slide 10 in a direction away from the lid rim 5 as soon as the locking element I8 comes to rest in the registry notch 31 (see FIG. 4); with the second cam 32 simultaneously acting through the control element 25 to hold the second lifting element 2% remote from the gasket 8.

Accordingly, only in this position, in which the handles 3 and 4 are in registry, are both lifting elements I3 and 2t) withdrawn for the gasket 8, whereby the same is seated on its sealing surface and seals the lid 2 against the vessel 1 so that pressure may be generated inside the cooker.

To provide for an opening of the sealed cooker, it is necessary to act by means of the actuator 37 via the bolt 16 on the first slide it? so that the locking element 18 may move out of the registry notch Till. This is done by depressing the key arm 27 of the actuator 37. Positively and automatically, the first lifting element 113 thereby is moved against the gasket h to lift the same from its sealing surface. in case there still is pressure in the cooker at the time of its opening, the steam will then escape through the opening i l, thereby alerting the operator. if the operator continues to rotate the lid despite this warning signal, the pressurized steam continues to escape, first through the opening l t, and soon through the opening Ill also, since the second cam releases in the course of further rotation the second slide llll for movement toward the lid 2 by force of the compression spring MT. in consequence, the second lifting element Jill also presses against the gasket ll.

Accordingly, the pressure inside the cooker will at least for the largest part have been exhausted by the time the locking claws ti and '7 of lid and vessel become disengaged.

The use and provision of the single spring ill. in accordance with the illustrated embodiment further increases the safety factor of the subject device, since a breaking of that spring affects all functions of the safety device so that the operator is alerted. This spring is moreover laterally protected by the lug or tongue ll'll which extends from the slide lltl into aperture in the slide ill.

The further embodiment of the subject invention shown in FIG. ti distinguishes itself from the embodiment lFlGS. l to mainly by the design of the handles. Short side handles 3, one of which is seen in FIG. ti, are attached to the vessel l and define the above-mentioned control cams Elll and 32. Corresponding lid handles i, one of which is seen in FlG. d, are likewise short. For this design, a differently shaped actuator El? is provided to save space and facilitate handling. The remaining parts of the cooker and safety device correspond moreover to their counterparts in FlGS. l to 5 and hear, therefore, like reference characters.

The actuator 37 is formed as a. sliding grip element and is integral with the first slide ill. This actuator 37 is located at the top of the slide lltl in a region remote from the lid El, and projects upwardly through a recess as of the lid handle t. The top surface 1% of the actuator Zl'l" is downwardly inclined as seen in a direction toward the end of the lid handle, and forms an area of pressure application by a linger, such as the thumb, of the operators hand that grips the lid handle during a cooker opening operation, By a displacement of the sliding grip actuator 3'7 in a direction toward the lid 13, the first slide tilt is moved in that same direction, whereby the unlocking and safety operations elaborately disclosed above are realized.

H03. '7 to llll show a pressure cooker in accordance with a further embodiment of the subject invention. This further embodiment concerns a safety device without the above mentioned second lifting element and associated parts, and without the safety feature of these parts outside the locking range.

The cooker lill il of H63. '7 to ill has a stem-shaped vessel handle ill attached to the vessel Mill. The cooker is closed by means of a lid ltlfl to which a likewise stern-shaped lid handle Edd is attached. MG. 7 shows the cooker in a closed position in which claws ins, which are bent out of the lid rirn lltlh' and one of which is seen in the figure, reach under corresponding claws ill? at the rim or" the vessel llllll and lock the lid onto the vessel. An annular gasket l'llll of rubber or rubberlike material is seated in the lid rim Th5 and seals the lid illEs and the vessel llllll relative to one another so as to permit a rise of pressure in the cooker. A safety device Mill is located in the lid handle This device Th9 comprises four parts which tit together without additional fasteners or connecting elements. These four parts comprise an actuator it'll, a slide lllll, spring lift and a guide lllFl. Each of the actuator i it), slide 71 l l and guide M3 is a single injectiom-nolded plastic piece.

As seen in MG. ll, the actuator llllll is substantially horizontally located in a slot-shaped recess ll ll la of the lid handle lllll l. This actuator lllll has two angularly disposed arrns lliilla and illllb. The arm 'lll lla is key shaped and projects laterally from the lid handle llllld in the quiescent state of the safety device M39 shown in the drawings. The second arrn llllb has a thickness which is considerably smaller than that of the arm llll lta, so that a step shown in dotted outline in Fill d is present at the lower side oi the actuator ll ill. The arm lllll b terminates in an eye lll hc by means of which the actuator is pivotaily mounted on a bolt lilo of the slide ,lllll. A lateral protrusion llli illb of the arm illtllr supporw the actuator at a wall portion of the slit llllldo for tilting; movement, so that the key-shaped artn may he swung into a recess llll'db adjacent the slit llll ln. in its quiescent position the actuator llltl rests with a point lll llc in the region of its outer angular ripen also against a wall portion of the slit il l ln.

in its upper region the slide lilll has a substantially the shape of a rectangular plate llll lib with a stepped recess llllllc into which the bolt llllln extends. The plate ll ill) terminates at its side which is adjacent the lid rim in a lug lllllcl (see FlG. it) which serves as a. pressure element and which extends into an opening lllllln in the lid rirn llli. 1 in omnilaterally recessed centerpiece lie is annexed to the lower side of the plate llllb and has a bore llll l. An end portion of a spring llllil is supported in the bore lid.

A projection illlf is formed at the lower side of the centerpiece lllle and projects downwardly beyond the lid handle to cooperate as a locking element with the guiding cam llltin of the vessel handle ilhlll. its seen in MG. lit, the projection iii if is rounded off at its back side.

The guide ll retains the slide lllll in a substantially oblong recess lib-dc of the lid handle ll fi d. The recess lit le extends in the direction of the center axis of the: lid handle ltl i, but is laterally offset from sue center axis for space-saving purposes.

Tne guide ll llEl has a substantially U'SlIZLPtZCl plan view which is shown in lFlG. in dotted outline. it is composed of two slide bars lilo with shoulders llli'lb and an interconnecting bight portion lllli c which rests with a projection llldd against the lid rirn Mill. The shoulders i113]; rest in corresponding elongate notches of the recess lt lc. The plate llllb is slidable on the bars llllfla and the centerpiece title of the slide llll is slidable therebetween. A bore M5 at the side oi the night portion llllllc which faces away from the lid rim is in alignment with the bore lid of the slide ill l. The other end of the spring illli'l is located therein.

Flt}. llll shows part of the top surface of the vessel handle lllii, together with a section of the projection lllllf which cooperates as a locking element with the guiding cam llloa. The guiding cam llltia, a registry notch tilt, and a shoulder lllltic which proceeds to the rim of the vessel bill are formed by the outline ofa recess lllld in the top side of the vessel handle The projection llllf cannot laterally be moved in the rest position of the safety device lltld shown in FlGS. 7 and 8. Accordingly, the projection llllllf locks the lid against rotary movement relative to the vessel il llll.

The illustrated safety device lid) is assembled. in the follow ing manner:

The actuator M ll is laterally inserted through the slit lllldu while the top side of the lid handle ltl i is preferably oriented downwardly. The slide lllill is inserted from above (i.e., through the lower side of the lid handle llll ll into the recess lll lc so that the bolt lllla engages the eye little of the actuator lid. The spring ill is first inserted into the bore lil l from the side of the lid handle which is to be attached to the lid rim. The guide trial is then inserted in the same direction into the recess whereby the free end of the spring lilo is supported in the bore lid of the bight portion ll: The spring M2 holds the guide M3 in a position. in which it projects beyond the outline of the lid handle at the mounting side. When the lid handle llld is attached to the lie the bight portion lllElc comes to rest with its projection llllfid at the lid rim ldfi. The spring M2 is compressed. After the lid handle has been attached to the lid, all parts of the safety device 1W9 are supported in the position shown in the drawing, without a necessity of at ional fastening elements.

The safety a vice llld corresponds in terms of construction and operation largely, in ticulars even identically, to the parts of the safety device of t l. to El comprising the first slide 10, the first lifting element 13, the locking element 18 and the actuator 37. A detailed elaboration of the operation of the safety device M39 is, therefore, unnecessary. The sliding movement of the rounded-off back side of the projection lllif during positioning and rotation of the lid may be sufficient to provide for such a compression of the spring 1 12 that the projection lllf snaps into the registry notch lldb without an actuation of the actuator 110. If the contents of the cooker are hot, whereby pressure forms immediately when the lid is positioned, an actuation of the actuator lllltl facilitates, however, the requisite rotary motion.

The invention is not limited in its scope to the illustrated embodiments. The slide, the lifting elements and the control cams may with the same cooperative relationship assume other forms of execution. it is particularly possible to provide an embodiment in which both slides are so interfitted that a first one of the lifting elements is tubularly hollow, while the second lifting element is slidable in the first lifting element. in this case it is only necessary to provide one opening in the lid rim whereby the overlapping lifting action of the lifting elements is unimpaired.

For a set of pressure cookers which have a common lid and an interlocking structure, which cooperates with the lid and is attachable to the cooking vessel, it is possible to provide in the lid handle a safety device according to the invention, and to provide the corresponding control cams or registry notches in a handle which is attached to the cooking vessel or to the interlocking structure.

iclaim:

l. A safety device for a steam pressure cooker, which steam pressure cooker comprises a cooking vessel, a lid connectable to and selectively removable from the cooking vessel, a sealing surface and a gasket engaging the sealing surface for releasably sealing the lid relative to the vessel, said safety device comprising in combination with said pressure cooker:

first means operatively associated with said gasket for selectively lifting the gasket from the sealing surface to permit the escape of steam from the vessel;

second means connected between said lid and cooking vessel for locking the lid against removal from the cooking vessel within a locking range and for selectively releasing the lid for removal from the vessel;

third means connected to said first and second means for actuating said first means to lift the gasket from the seal ing surface prior to each release by said second means of said lid for removal from the vessel; and

fourth means operatively associated with said gasket for selectively lifting said gasket from the sealing surface to permit the escape of steam from the vessel in response to displacement of said second means relative to said locking range.

2. A safety device as claimed in claim ll, wherein said fourth means include:

gasket-lifting means movable against said gasket for lifting the gasket, and selectively movable away from the gasket for permitting engagement of the gasket with the sealing surface; and

control cam means operatively associated with said gasketlifting means and coupled to said cooking vessel for mov' ing the gasket-lifting means against the gasket to lift the gasket as long as said second means are displaced relative to the locking range, and for selectively moving the gasket-lifting means away from the gasket to permit engagement of the gasket with the sealing surface upon positioning of said second means in the locking range.

3. A safety device as claimed in claim ll, wherein:

said first means include gasket-lifting means movable against said gasket for lifting the gasket, and selectively movable said from the gasket for permitting engagement of the gasket with the sealing surface;

said second means include locking cam means coupled between said lid and cooking vessel for locking the lid within said locking range and for selectively releasing the lid for removal from the vessel; and

said third means include means for positively coupling said gasket lifting means to said locking cam means.

4. A safety device as claimed in claim 3, wherein said fourth means include:

further gasket-lifting means movable against said gasket for lifting the gasket, and selectively movable away from the gasket for permitting engagement of the gasket with the sealing surface; and

control cam means operatively associated with said further gasket-lifting means and coupled to said cooking vessel for moving the further gasket-lifting means against the gasket to lift the gasket as long as said second means are displaced relative to the locking range, and for selectively moving the further gasket'lifting means away from the gasket to permit engagement of the gasket with the sealing surface upon positioning of said second means in the locking range.

5. A safety device as claimed in claim 4, wherein:

said locking carn means and said control cam means are constructed to permit a positioning of said gasket-lifting means and said further gasket-lifting means away from the gasket only within said locking range.

6. A safety device as claimed in claim 4, wherein:

said pressure cooker includes a vessel handle attached to said vessel, and a lid handle attached to said lid and movable into registry with said vessel handle;

said locking cam means include a locking cam in said vessel handle;

said control cam means include a control cam in said vessel handle; and

said gasket-lifting means and further gasket-lifting means,

and said positive coupling means are mounted substantially in said lid handle.

7. A safety device as claimed in claim 1, wherein:

said pressure cooker includes a vessel handle attached to said vessel, and a lid handle attached to said lid and movable into registry with said vessel handle;

said second means include a locking cam in said vessel handle, and a first slide structure mounted in said lid handle and having a first cam follower engageable with said locking cam in the vessel handle for selectively locking and releasing the lid relative to the cooking vessel;

said first means and at least part of said third means are integral with said first slide structure; and

said fourth means include a control cam in said vessel handle, and a second slide structure mounted in said lid handle and having a gasket lifter, and including a second cam follower engageable with said control cam in said vessel handle for selectively moving the gasket lifter against and alternatively away from said gasket.

8. A safety device as claimed in claim 7, wherein:

said locking cam has a registry notch for said first cam follower; and

said control cam projects in a direction toward said registry notch.

9. A safety device as claimed in claim 7, including:

a single spring for biasing said first and second slide structures away from one another.

10. A safety device as claimed in claim 7, including:

manually actuable means coupled to said first slide structure for selectively actuating said first cam follower, said first means and said third means.

11. A safety device as claimed in claim it), wherein:

said manually actuable means include an actuating member integral with said first slide structure, and having a finger grip portion projecting from said lid handle.

12. A safety device as claimed in claim M9, wherein:

said manually actuable means include an actuating member coupled to said first slide structure and having a keyshaped actuating member projecting laterally from said lid handle.

13. A safety device as claimed in claim 10, wherein said manually actuable means include:

El ,o li l-l 8 a first cam pivotally coupled to said first slide structure and locally engaging a portion of said lid handle for tilting movement relative to said lid handle; and

a second arm connected and extending at an angle to said first arm and defining an actuating key projecting laterally from the lid handle.

M. A safety device for a steam pressure cooker, which steam pressure cooker comprises a cooking vessel, a lid connectable to and selectively removable from the cooking vessel, a sealing surface and a gasket engaging the sealing surface for releasably sealing the lid relative to the vessel, said safety device comprising in combination with said pressure cooker;

first means operatively associated with said gasket for selectively lifting the gasket from the sealing surface to permit the escape of steam from the vessel;

second means connected between said lid and cooking vessel for locking the lid against removal from the cooking vessel within a locking range and for selectively releasing the lid for removal from the vessel; and

third means connected to said first and second means for actuating said first means to lift the gasket from the sealing surface prior to each release by said second means of said lid for removal from the vessel.

15. A safety device as claimed in claim Mi, wherein:

said first means include gasket-lifting means movable against said gasket for lifting the gasket, and selectively movable away from the gasket for permitting engagement of the gasket with the sealing surface;

said second means include locking cam means coupled between said lid and cooking vessel for locking the lid within said locking range and for selectively releasing the lid for removal from the vessel; and

said third means include means for positively coupling said gasket-lifting means to said locking earn means.

in. A safety device as claimed in claim 15, wherein:

said pressure cooker includes a vessel handle attached to said vessel, and a lid handle attached to said lid and movable into registry with said vessel handle;

said locking cam means include a locking cam in said vessel handle defining a registry notch, and sadd locking cam means further include a locking element coupled to said positive coupling means and selectively insertable into said registry notch; and

said gasket-lifting means and said positive coupling means are mounted substantially in said lid handle.

l7. A safety device as claimed in claim M, wherein:

said pressure cooker includes a vessel handle attached to said vessel, and a lid handle attached to said lid and movable into registry with said vessel handle;

said second means include a locking cam in said vessel handle, and a slide structure mounted in said lid handle and having an appendant locking element selectively inscrtable into said locking cam in the vessel handle; and

said first means and at least part of said third means are integral with said slide structure.

lid. A safety device as claimed in claim 17, including:

a guide for said slide structure mounted in said lid handle;

and

a spring between said guide and slide structure for biasing said slide structure relative to said lid.

19. A safety device as claimed in claim l7, including:

manually actuable means coupled to said slide structure for selectively actuating said locking element and positively said first means.

Ell. A safety device as claimed in claim lll wherein:

said manually actuable means include an actuating member coupled to said slide structure and having a key-shaped actuating mem'oer projecting laterally from said lid handle.

Zll. A safety device as claimed in claim l9, wherein said manually actuable means include:

a first arm pivotally coupled to said first slide structure and locally engaging a portion of said lid handle for tilting movement relative to said lid handle; and

a second arm connected and extending at an angle to said first arm and defining an actuating key projecting laterally from the lid handle.

mg UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,645,418 Dated February 29, 1972 lnvent fl Karl-Oskar Oberlinder It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 4, line 68, "for" should be --from-. Column 5, line 24, "of" should be inserted after --embodiment-. Column 6, line 11, "Its" should be ----its--. Column 6, line 11, "a" should be cancelled. Column 6, line 67, "lie" should be --lid--. Column 7, line 70, "said" should be -away--. Column 9, line 1, "cam" should be --arm-.

Signed and sealed this 3rd day 9 September 1974' QSEAL) Attes-tz I I C. MARSHALL DANN gfi t ng i ier Conmiiissioner of Patents 

1. A safety device for a steam pressure cooker, which steam pressure cooker comprises a cooking vessel, a lid connectable to and selectively removable from the cooking vessel, a sealing surface and a gasket engaging the sealing surface for releasably sealing the lid relative to the vessel, said safety device comprising in combination with said pressure cooker: first means operatively associated with said gasket for selectively lifting the gasket from the sealing surface to permit the escape of steam from the vessel; second means connected between said lid and cooking vessel for locking the lid against removal from the cooking vessel within a locking range and for selectively releasing the lid for removal from the vessel; third means connected to said first and second means for actuating said first means to lift the gasket from the sealing surface prior to each release by said second means of said lid for removal from the vessel; and fourth means operatively associated with said gasket for selectively lifting said gasket from the sealing surface to permit the escape of steam from the vessel in response to displacement of said second means relative to said locking range.
 2. A safety device as claimed in claim 1, wherein said fourth means include: gasket-lifting means movable against said gasket for lifting the gasket, and selectively movable away from the gasket for permitting engagement of the gasket with the sealing surface; and control cam means operatively associated with said gasket-lifting means and coupled to said cooking vessel for moving the gasket-lifting means against the gasket to lift the gasket as long as said second means are displaced relative to the locking range, and for selectively moving the gasket-lifting means away from the gasket to permit engagement of the gasket with the sealing surface upon positioning of said second means in the locking range.
 3. A safety device as claimed in claim 1, wherein: said first means include gasket-lifting means movable against said gasket for lifting the gasket, and selectively movable said from the gasket for permitting engagement of the gasket with the sealing surface; said second means include locking cam means coupled between said lid and cooking vessel for locking the lid within said locking range and for selectively releasing the lid for removal from the vessel; and said third means include means for positively coupling said gasket lifting means to said locking cam means.
 4. A safety device as claimed in claim 3, wherein said fourth means include: further gasket-lifting means movable against said gasket for lifting the gasket, and selectively movable away from the gasket for permitting engagement of the gasket with the sealing surface; and control cam means operatively associated with said further gasket-lifting means and coupled to said cooking vessel for moving the further gasket-lifting means against the gasket to lift the gasket as long as said second means are displaced relative to the locking range, and for selectively moving the further gasket-lifting means away from the gasket to permit engagement of the gasket with the sealing surface upon positioning of said second means in the locking range.
 5. A safety device as claimed in claim 4, wherein: said locking cam means and said control cam means are constructed to permit a positioning of said gasket-lifting means and said further gasket-lifting means away from the gasket only within said locking range.
 6. A safety device as claimed in claim 4, wherein: said pressure cooker includes a vessel handle attached to said vessel, and a lid handle attached to said lid and movable into registry with said vessel handle; said lockIng cam means include a locking cam in said vessel handle; said control cam means include a control cam in said vessel handle; and said gasket-lifting means and further gasket-lifting means, and said positive coupling means are mounted substantially in said lid handle.
 7. A safety device as claimed in claim 1, wherein: said pressure cooker includes a vessel handle attached to said vessel, and a lid handle attached to said lid and movable into registry with said vessel handle; said second means include a locking cam in said vessel handle, and a first slide structure mounted in said lid handle and having a first cam follower engageable with said locking cam in the vessel handle for selectively locking and releasing the lid relative to the cooking vessel; said first means and at least part of said third means are integral with said first slide structure; and said fourth means include a control cam in said vessel handle, and a second slide structure mounted in said lid handle and having a gasket lifter, and including a second cam follower engageable with said control cam in said vessel handle for selectively moving the gasket lifter against and alternatively away from said gasket.
 8. A safety device as claimed in claim 7, wherein: said locking cam has a registry notch for said first cam follower; and said control cam projects in a direction toward said registry notch.
 9. A safety device as claimed in claim 7, including: a single spring for biasing said first and second slide structures away from one another.
 10. A safety device as claimed in claim 7, including: manually actuable means coupled to said first slide structure for selectively actuating said first cam follower, said first means and said third means.
 11. A safety device as claimed in claim 10, wherein: said manually actuable means include an actuating member integral with said first slide structure, and having a finger grip portion projecting from said lid handle.
 12. A safety device as claimed in claim 10, wherein: said manually actuable means include an actuating member coupled to said first slide structure and having a key-shaped actuating member projecting laterally from said lid handle.
 13. A safety device as claimed in claim 10, wherein said manually actuable means include: a first cam pivotally coupled to said first slide structure and locally engaging a portion of said lid handle for tilting movement relative to said lid handle; and a second arm connected and extending at an angle to said first arm and defining an actuating key projecting laterally from the lid handle.
 14. A safety device for a steam pressure cooker, which steam pressure cooker comprises a cooking vessel, a lid connectable to and selectively removable from the cooking vessel, a sealing surface and a gasket engaging the sealing surface for releasably sealing the lid relative to the vessel, said safety device comprising in combination with said pressure cooker; first means operatively associated with said gasket for selectively lifting the gasket from the sealing surface to permit the escape of steam from the vessel; second means connected between said lid and cooking vessel for locking the lid against removal from the cooking vessel within a locking range and for selectively releasing the lid for removal from the vessel; and third means connected to said first and second means for actuating said first means to lift the gasket from the sealing surface prior to each release by said second means of said lid for removal from the vessel.
 15. A safety device as claimed in claim 14, wherein: said first means include gasket-lifting means movable against said gasket for lifting the gasket, and selectively movable away from the gasket for permitting engagement of the gasket with the sealing surface; said second means include locking cam means coupled between said lid and cooking vessel for locking the lid within said locking range and For selectively releasing the lid for removal from the vessel; and said third means include means for positively coupling said gasket-lifting means to said locking cam means.
 16. A safety device as claimed in claim 15, wherein: said pressure cooker includes a vessel handle attached to said vessel, and a lid handle attached to said lid and movable into registry with said vessel handle; said locking cam means include a locking cam in said vessel handle defining a registry notch, and said locking cam means further include a locking element coupled to said positive coupling means and selectively insertable into said registry notch; and said gasket-lifting means and said positive coupling means are mounted substantially in said lid handle.
 17. A safety device as claimed in claim 14, wherein: said pressure cooker includes a vessel handle attached to said vessel, and a lid handle attached to said lid and movable into registry with said vessel handle; said second means include a locking cam in said vessel handle, and a slide structure mounted in said lid handle and having an appendant locking element selectively insertable into said locking cam in the vessel handle; and said first means and at least part of said third means are integral with said slide structure.
 18. A safety device as claimed in claim 17, including: a guide for said slide structure mounted in said lid handle; and a spring between said guide and slide structure for biasing said slide structure relative to said lid.
 19. A safety device as claimed in claim 17, including: manually actuable means coupled to said slide structure for selectively actuating said locking element and positively said first means.
 20. A safety device as claimed in claim 19, wherein: said manually actuable means include an actuating member coupled to said slide structure and having a key-shaped actuating member projecting laterally from said lid handle.
 21. A safety device as claimed in claim 19, wherein said manually actuable means include: a first arm pivotally coupled to said first slide structure and locally engaging a portion of said lid handle for tilting movement relative to said lid handle; and a second arm connected and extending at an angle to said first arm and defining an actuating key projecting laterally from the lid handle. 